Heat causing some fish die-offs in west central Minnesota

The hot weather is blamed for northern pike die-offs reported in Willmar and Foot Lakes as well as Mud Lake north of New London.

SPICER — The record heat wave has caused fish kills across southern Minnesota, and fisheries personnel with the Minnesota Department of Natural Resources in Spicer are keeping a watchful eye on local lakes.
As of earlier this week, the area had escaped any reports of large or widespread fish kills, according to information from Dave Coahran, fisheries supervisor in Spicer.
However, there have been die-offs attributed to the hot weather.
Conservation Officer Jeff Denz responded to the discovery that several dozen northern pike had died in Willmar and Foot Lakes in Willmar. There was a similar report of a northern pike kill in Mud Lake north of New London.
There were also reports of a walleye kill in Wood Lake, located south of Granite Falls. Coahran said there were reports that numbers of walleye had also congregated and were very lethargic, to the point that they could be scooped up.
Fortunately, no reports have been received of tullibee die-offs in either Green Lake or Koronis Lake, according to the fisheries manager. The two lakes are among the southern-most of lakes in Minnesota capable of holding tullibee, also known as cisco.
If warm conditions reduce the oxygen level in the deeper, cooler water they prefer, the fish will rise. Large and medium-sized tullibees are vulnerable if the upper water is too warm.

— Tom Cherveny